"My God, what must it be like in your funny little brains… it must be so boring." Benedict Cumberbatch, looking for all the world like a rather pretty gargoyle, fallen among us with a rude shock and some tweedy darks to cloak his marbled limbs, didn't say this nastily, when waiting for Lestrade and Watson to catch up with his every deduction. He said it with a kind of detached benevolent bemusement, a state of affairs that was actually starting to trouble him – hence his wary need for someone like Watson; and, hence, along with everything else that this wonder of a series promises – clues, deductions, redness of mists and of herrings, evil, a buddy-movie, Watson's chasing of Mycroft's sinister but flaky female assistant – we get the anticipation of a superman bowing to a mensch, and learning from us mortals. Oh, it's all here.

Every "high-achieving sociopath" – as Sherlock Holmes happily and curtly described himself – needs his Watson. Low-achieving sociopaths, if I remember my Sociopathy module 2:3 correctly, are the ones filling our prisons; the high achievers are the ones who have learned, if not quite to laugh and cry and empathise at the right times, at least to understand why they should be doing so and thus go some way to pretending, like Hannibal Lecter: so John Watson will help decide, over the next few weeks, whether his new friend becomes simply a better mimic or, actually, a human being.

I'd like to think that co-creators Steven Moffat and Mark Gatiss, real humans, don't think, when comparing what they've just done to the output of most "new" TV creativity, "What must it be like in your funny little brains…" but they would have fair justification. Sherlock is, to my mind, even better than Doctor Who, with which the pair have been so closely involved.

The genius lies in the willingness to adapt Sherlock to modernity, while keeping just enough Gothic mystery to intrigue, which is of course slightly Whovian in itself, no surprise, but, honestly, this is more adult and less occasionally silly. Cumberbatch's fabulous Sherlock may look a little Victorian, admittedly, but there's no easy timeshift device: he is utterly 21st-century man, just with a very fat brain. He does, for instance, the wonderful thing, surely the only way forward for all of us, of not wilfully ignoring Google, far from it, but using it to supplement what he's seen, and what he knows, rather than thinking it actually exists so he can just type in "who did The cri'me then?" before going off wrongly to push burning faeces under the door of an innocent watchmaker in Dieppe or some such.

So there is much (but still not enough, you can never get enough) of that Holmesian deduction stuff from observation – that frayed trouser hem tells me his aunt's fourth wooden leg gave her gyp every second autumn, and the like – but this time with Sim cards and USB ports, and there's fine synergy between old and new, best of both. Also, for such modernity, London, in this filming, had an oddly Gothic feel. Marylebone still does that. Somehow Moffat and Gatiss have sewn old and new into a very modern, very human drama, and what fun they must have had doing so, and it shows, and Sundays are great again. And pretty much all of the clues and the plot held up, on a rewatching and even with subtitles, other than the savage unlikelihood of finding three working red phone boxes extant in Brixton, if I'm being picky.

One of the surprises is Martin Freeman, as John Watson: crippled not, as so boringly usually, by a lightweight intelligence but by an actual limp, psychosomatic though it may largely be, and by Afghanistan trauma. He's complex, and better drawn than at any time since the original novels, and Freeman caught this whole subtle new persona with magnificence, and this part might deservedly free him, finally, from The Office, or too many of those things where the likes of Hugh Grant and chums run past him on the way to weddings.

So men love it because of the clevers, and the clues, and the chases. Children, even, will get echoes of that bloody boy-wizard thing in the constant terrified not-saying of the name Moriarty. Women will love it because of the clues, because they're the kind of clues that women like – non-matching varnish and lippie, and why is the hood of the coat still wet, that kind of thing – and, more than possibly, because of Cumberbatch. Although my girlfriend swears she's only fascinated with him because he was "named after those waistbands you wear with tuxes". What must it be like in your etc.

It doesn't take any brains at all, apparently, nor any kind of certification, to become a pastor in an African church in London: just a filthy level of corruption, a keen amateur interest in child-abuse and a poor, desperate, congregation over-willing to believe that their misfortunes are all the fault of witchcraft, often emanating from their own children. This was as good as Dispatches gets: searing, astonishing, legalled. Not all pastors, of course, but the ones named after Dispatches had gone undercover. Dieudonné Tukala, "Archbishop" Gilbert Deya – as a newspaper I want us to watch these men every week, forever – have had obscene amounts of money, and more than a hint of underage sexual favours, by trading on the willingness of undereducated parents to pay money they don't have, or even offer their daughters for "deliverance", for the "pastor" to assure them that devils had been flung out. This is now illegal in Africa, but legal in London. Here, police are wary of intruding because of fears of accusations of "racism". Parents still pay for exorcisms, and then a blessing, at the hands of these "pastors". They used to call it simony. But I don't think the Bible has a word, and it has a lot of them, to express the revulsion I felt at this misuse of trust: watch this film, please, and someone somewhere keep tabs.

I have hope, still, a bit, for Orchestra United, in which young and impossibly bloody nice conductor James Lowe tries to create a Manchester orchestra from people who don't normally have "access" to orchestras, ie roughly poor or often black people. By and large they were all fine, keen musicians, and for a while it seemed like it all might just go right. And then, for some unexplained reason – was this just Channel 4 doing this, to make it not work, or do real people actually still believe in this crap? – the important weekend away before the concert was spent doing "bonding exercise workshops", when it might have been an idea to train some of them to listen to each other playing, and work out how to play together, because, for all the individual instrumental skills, they were almost entirely unused to interaction. Concerted, orchestrated interaction; there's a reason why bits of those first two words have become blessed as nouns.

The moment they tried to tune up you could see James shudder. Twelve seconds later he dropped, with dwindling hope, his baton for that famous opening bar of Finlandia. It was of such horrid halting atonal inadequacy it was as if we had stumbled upon a completely different programme, one exposing an admittedly bizarre but utterly dedicated secret sect of working-class Mancunians whose lifelong aim is to somehow perennially pain the memory of Sibelius.